Semiconductor device and method of manufacture thereof, circuit board and electronic instrument

ABSTRACT

A method of manufacturing a semiconductor device comprises: a first step of interposing a thermosetting anisotropic conductive material  16  between a substrate  12  and a semiconductor chip  20 ; a second step in which pressure and heat are applied between the semiconductor chip  20  and the substrate  12 , an interconnect pattern  10  and electrodes  22  are electrically connected, and the anisotropic conductive material  16  is spreading out beyond the semiconductor chip  20  and is cured in the region of contact with the semiconductor chip  20 ; and a third step in which the region of the anisotropic conductive material  16  other than the region of contact with the semiconductor chip  20  is heated.

This is a Continuation of application Ser. No. 09/486,317 filed Feb. 25,2000, now U.S. Pat. No. 6,462,289 which in turn is a 371 ofPCT/JP99/03420 filed Jun. 25, 1999. The entire disclosure of the priorapplication(s) is hereby incorporated by reference herein in itsentirety.

TECHNICAL FIELD

The present invention relates to a semiconductor device and method ofmanufacture thereof, and to a circuit board and an electronicinstrument.

BACKGROUND ART

In recent years, with the increasing compactness of electronicinstruments, semiconductor device packages adapted to high densitymounting are in demand. In response to this, surface mounting packagessuch as a ball grid array (BGA) and a chip scale/size package (CSP) havebeen developed. In a surface mounting package, a substrate may be usedwhich has formed thereon an interconnect pattern for connection to asemiconductor chip.

In a conventional surface mounting package, since there is a step ofproviding a protective film to protect the interconnect pattern and soforth, it is has been difficult to improve the productivity.

The present invention solves this problem, and has as its objective theprovision of a method of manufacturing a semiconductor device and asemiconductor device manufactured by the method, of a circuit board andof an electronic instrument, having excellent reliability andproductivity.

DISCLOSURE OF THE INVENTION

(1) A method of manufacturing a semiconductor device of the presentinvention comprises:

a first step of interposing an adhesive between a surface of a substrateon which an interconnect pattern is formed and a surface of asemiconductor chip on which electrodes are formed;

a second step of applying energy between the semiconductor chip and thesubstrate, electrically connecting the interconnect pattern and theelectrodes, and making adhesive properties of the adhesive effective inthe region of contact with the semiconductor chip while the adhesivespreading out beyond the semiconductor chip; and

a third step of applying energy to the region of the adhesive other thanthe region of contact with the semiconductor chip.

(2) In this method of manufacturing a semiconductor device,

the adhesive may be thermosetting;

the energy applied in the second step may be pressure and heat; and

the energy applied in the third step may be heat.

The adhesive is cured in the region of contact with the semiconductorchip, and thereafter, the region other than the region of contact isheated and cured. Thus the adhesive is also cured in the region where itspreads out beyond the semiconductor chip. By means of this, thepossibility of the adhesive coming apart from the substrate and allowingthe ingress of water, leading to migration of the interconnect patterncan also be prevented. Since the adhesive is cured, the inclusion ofwater can be prevented.

(3) In this method of manufacturing a semiconductor device, theinterconnect pattern and the electrodes may be electrically connected byconductive particles dispersed in the adhesive.

Since the interconnect pattern and electrodes are electrically connectedby the conductive particles, a semiconductor device can be manufacturedby a method of excellent reliability and productivity.

(4) In this method of manufacturing a semiconductor device, before thefirst step, the adhesive may be previously disposed on the surface ofthe semiconductor chip on which the electrodes are formed.

(5) In this method of manufacturing a semiconductor device, before thefirst step, the adhesive may be previously disposed on the surface ofthe substrate on which the interconnect pattern is formed.

(6) In this method of manufacturing a semiconductor device, in the thirdstep, energy may be applied to a portion of the adhesive at which curingis not completed in the second step.

(7) In this method of manufacturing a semiconductor device, in the thirdstep, the adhesive may be heated by a heating jig.

(8) In this method of manufacturing a semiconductor device, anonadhesive layer having high nonadhesive properties to the adhesive maybe interposed between the heating jig and the adhesive, and the adhesiveis heated.

(9) In this method of manufacturing a semiconductor device, the heatingjig may be provided with the nonadhesive layer.

(10) In this method of manufacturing a semiconductor device, thenonadhesive layer may be disposed on the adhesive.

(11) In this method of manufacturing a semiconductor device, in thethird step, energy may be applied to the adhesive without contacting theadhesive.

(12) This method of manufacturing a semiconductor device may furthercomprise:

a reflow step in which solder balls connecting to the interconnectpattern are formed on the substrate,

wherein the third step may be carried out in the reflow step.

(13) This method of manufacturing a semiconductor device may furthercomprise:

a reflow step in which in addition to the semiconductor chip, anotherelectronic component is electrically connected to the interconnectpattern;

wherein the third step may be carried out in the reflow step.

(14) In this method of manufacturing a semiconductor device, after thethird step, the substrate may be cut in a region other than a region inwhich the adhesive contacts with the semiconductor chip.

(15) In this method of manufacturing a semiconductor device, in thesecond step, the adhesive may be caused to surround at least a part of alateral surface of the semiconductor chip.

Since the adhesive covers at least a part of the lateral surface of thesemiconductor chip, not only is the semiconductor chip protected frommechanical damage, but also water can be prevented from reaching theelectrodes, and corrosion can be prevented.

(16) In this method of manufacturing a semiconductor device, theadhesive may be provided before the first step at a thickness greaterthan the interval between the semiconductor chip and the substrate afterthe second step, and may spread out beyond the semiconductor chip byapplying pressure between the semiconductor chip and the substrate inthe second step.

(17) In this method of manufacturing a semiconductor device, theadhesive may include a shading material.

Since the adhesive includes a shading material, light can be preventedfrom reaching the surface of the semiconductor chip having theelectrodes, and so malfunction of the semiconductor chip can beprevented.

(18) A method of manufacturing a semiconductor device according to thepresent invention comprises:

a first step of interposing an adhesive between a surface of a substrateon which an interconnect pattern is formed and a surface of asemiconductor chip on which electrodes are formed;

a second step of electrically connecting the interconnect pattern andthe electrodes, and curing the adhesive at least in a position betweenthe semiconductor chip and the substrate while the adhesive spreadingout beyond the semiconductor chip; and

a third step of cutting the substrate in a region in which the adhesivespreads out beyond the semiconductor chip.

According to the present invention, the adhesive is cut after it isprovided spreading out beyond the semiconductor chip. Thus, there is norequirement for accurate positioning with respect to the semiconductorchip at the same size as the semiconductor chip. Since the adhesive iscut in the region spreading out beyond the semiconductor chip togetherwith the substrate, the entire surface of the substrate is covered bythe adhesive so that migration and the like of the interconnect patterncan be prevented.

(19) In this method of manufacturing a semiconductor device, theadhesive may be a thermosetting adhesive, and heat may be applied to theadhesive in the second step.

(20) In this method of manufacturing a semiconductor device, theadhesive may be a thermoplastic adhesive, and the adhesive may be cooledin the second step.

(21) In this method of manufacturing a semiconductor device, theinterconnect pattern and the electrodes may be electrically connected byconductive particles dispersed in the adhesive.

(22) In this method of manufacturing a semiconductor device, before thefirst step, the adhesive may be previously disposed on the surface ofthe semiconductor chip on which the electrodes are formed.

(23) In this method of manufacturing a semiconductor device, before thefirst step, the adhesive may be previously disposed on the surface ofthe substrate on which the interconnect pattern is formed.

(24) In this method of manufacturing a semiconductor device, in thethird step, a cutting position may be in a region outside an end of theinterconnect pattern of the substrate.

(25) In this method of manufacturing a semiconductor device,

in the second step, the whole of the adhesive may be cured; and

in the third step, the cured adhesive may be cut.

Since the cured adhesive is cut, the cutting can be carried out easily.

(26) In this method of manufacturing a semiconductor device, in thesecond step, the adhesive may be caused to surround at least a part of alateral surface of the semiconductor chip.

Since the adhesive covers at least a part of the lateral surface of thesemiconductor chip, not only is the semiconductor chip protected frommechanical damage, but also water can be prevented from reaching theelectrodes, and corrosion can be prevented.

(27) In this method of manufacturing a semiconductor device, theadhesive may be provided before the first step at a thickness greaterthan the interval between the semiconductor chip and the substrate afterthe second step, and may spread out beyond the semiconductor chip byapplying pressure between the semiconductor chip and the substrate inthe second step.

(28) In this method of manufacturing a semiconductor device, theadhesive may include a shading material.

Since the adhesive includes a shading material, light can be preventedfrom reaching the surface of the semiconductor chip having theelectrodes, and so malfunction of the semiconductor chip can beprevented.

(29) A semiconductor device according to the present inventioncomprises:

a semiconductor chip having electrodes; a substrate having aninterconnect pattern; and a thermosetting adhesive;

wherein the electrodes and the interconnect pattern are electricallyconnected; and

wherein the adhesive is interposed between a surface of the substrate onwhich the interconnect pattern is formed and a surface of thesemiconductor chip on which the electrodes are formed, and spreads outbeyond the semiconductor chip, and the whole of the adhesive is cured.

According to the present invention, the adhesive is also cured in aregion outside that of contact with the semiconductor chip. Thus, thepossibility of the adhesive coming apart from the substrate and allowingthe ingress of water, leading to migration of the interconnect patterncan be prevented. Also, since all of the adhesive is cured, theinclusion of water can be prevented.

(30) In this semiconductor device, conductive particles may be dispersedin the adhesive to form an anisotropic conductive material.

Since the interconnect pattern and electrodes are electrically connectedby the anisotropic conductive material, the reliability and productivityare excellent.

(31) In this semiconductor device, the anisotropic conductive materialmay be provided to cover the whole of the interconnect pattern.

(32) In this semiconductor device, the adhesive may cover at least apart of a lateral surface of the semiconductor chip.

Since the adhesive covers at least a part of the lateral surface of thesemiconductor chip, the semiconductor chip is protected from mechanicaldamage. Additionally, since the semiconductor chip is covered by theadhesive as far as a position remote from the electrodes, water can beprevented from reaching the electrodes, and corrosion can be prevented.

(33) In this semiconductor device, the adhesive may include a shadingmaterial.

Since the adhesive includes a shading material, light can be preventedfrom reaching the surface of the semiconductor chip having theelectrodes, and so malfunction of the semiconductor chip can beprevented.

(34) A semiconductor device according to the present invention ismanufactured by the above-described method.

(35) On a circuit board according to the present invention, theabove-described semiconductor device is mounted.

(36) An electronic instrument according to the present invention has theabove-described circuit board.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1D show a method of manufacturing a semiconductor device inaccordance with a first embodiment relating to the present invention;

FIGS. 2A and 2B show a modification of the first embodiment;

FIGS. 3A and 3B show a method of manufacturing a semiconductor device inaccordance with a second embodiment relating to the present invention;

FIGS. 4A and 4B show a method of manufacturing a semiconductor device inaccordance with a third embodiment relating to the present invention;

FIGS. 5A and 5B show a method of manufacturing a semiconductor device inaccordance with a fourth embodiment of the present invention;

FIG. 6 shows a circuit board on which is mounted a semiconductor devicein accordance with the embodiment of the present invention; and

FIG. 7 shows an electronic instrument having a circuit board on which ismounted a semiconductor device in accordance with the embodiment of thepresent invention.

BEST MODE FOR CARRING OUT THE INVENTION

A preferred embodiment of the present invention will be described, withreference to the drawings.

First Embodiment

A method of manufacturing a semiconductor device in accordance with thefirst embodiment is shown in FIGS. 1A to 1D. In this embodiment, asubstrate 12 is used which has an interconnect pattern 10 formed on atleast one surface 18, as shown in FIG. 1A.

The substrate 12 may be a flexible substrate formed of an organicmaterial, a metal substrate formed of an inorganic material, or acombination of these. As a flexible substrate may be used a tapecarrier. If the electric conductivity of the substrate 12 is high, aninsulating film is formed between the substrate 12 and the interconnectpattern 10 and on inner surfaces of through holes 14. In addition, theinsulating film may also be formed on a surface of the substrateopposite to the surface on which the interconnect pattern 10 is formed.

The through holes 14 are formed in the substrate 12, and theinterconnect pattern 10 is formed on the substrate, covering the throughholes 14. Lands 17 for external electrodes are formed over the throughholes 14, as part of the interconnect pattern 10.

An anisotropic conductive material 16, as one example of an adhesive, isprovided on a thus obtained substrate 12. In the description thatfollows, an anisotropic conductive material is given as an example of anadhesive. The anisotropic conductive material 16 comprises an adhesive(binder) in which are dispersed conductive particles (conductivefiller), and in some cases a dispersant is added. The anisotropicconductive material 16 could be previously formed as a sheet that isaffixed to the substrate 12, or it could equally well be provided as aliquid on the substrate 12. The anisotropic conductive material 16 maybe provided to be larger than a surface 24 of a semiconductor chip 20 onwhich electrodes 22 are provided, or may be provided in a quantity to besmaller than the surface 24, then compressed so as to spread out beyondthe surface 24.

Alternatively, the anisotropic conductive material 16 may be provided onthe surface 24 of the semiconductor chip 20, in a quantity to becompressed so as to spread out beyond the surface 24. It should be notedthat even if an adhesive not including conductive particles is used, theelectrodes 22 and interconnect pattern 10 can be electrically connected.

In this embodiment, a thermosetting adhesive is used as the anisotropicconductive material, and the anisotropic conductive material 16 mayfurther include a shading material. As a shading material can be used,for example, a black dye or black pigment dispersed in an adhesiveresin.

As the adhesive may be used a thermosetting adhesive as typified by anepoxy type, or a photocurable adhesive as typified by an epoxy oracrylate type. Further, the type of adhesive cured by electron beam, ora thermoplastic (thermal adhesion) type of adhesive may equally be used.In the following description, if an adhesive other than thermosetting isused, the provision of energy should be substituted in place of theapplication of heat or pressure.

Next, the semiconductor chip 20 is mounted on the anisotropic conductivematerial 16, for example. In more detail, the semiconductor chip 20 ismounted such that the surface 24 of the semiconductor chip 20 on whichthe electrodes 22 are formed faces the anisotropic conductive material16. Moreover, the semiconductor chip 20 is disposed so that the eachelectrode 22 is positioned over a land (not shown in the figures) forconnection of the electrodes to the interconnect pattern 10. It shouldbe noted that the semiconductor chip 20 may have the electrodes 22formed on two edges only, or may have the electrodes 22 formed on fouredges. The electrodes 22 are commonly in the form of projections made ofgold, solder or the like provided on aluminum pads. The electrodes 22may be formed on the interconnect pattern 10 side in the form of suchprojections or projections formed by etching the interconnect pattern10.

By means of the above process, the anisotropic conductive material 16 ispositioned between the surface 24 of the semiconductor chip 20 on whichthe electrodes 22 are formed and the surface 18 of the substrate 12 onwhich the interconnect pattern 10 is formed. A jig 30 is then used topress a surface 26 of the semiconductor chip 20 which is opposite to thesurface 24 on which the electrodes 22 are formed such that thesemiconductor chip 20 is subjected to pressure in the direction of thesubstrate 12. Alternatively, pressure may be applied between thesemiconductor chip 20 and the substrate 12. Even if the anisotropicconductive material 16 as an adhesive is provided within the area of thesurface 24 of the semiconductor chip 20, the applied pressure causes itto spread out beyond the surface 24. The jig 30 has an internal heater32, and applies heat to the semiconductor chip 20. It should be notedthat considering the requirement as far as possible to apply heat alsoto the spread out portion of the anisotropic conductive material 16, thejig 30 used preferably has a greater plan area than the plan area of thesemiconductor chip 20. In this way, heat can easily be applied to theperiphery of the semiconductor chip 20.

Thus, as shown in FIG. 1B, the electrodes 22 of the semiconductor chip20 and the interconnect pattern 10 are electrically connected throughthe conductive particles of the anisotropic conductive material 16.According to this embodiment, since the interconnect pattern 10 andelectrodes 22 are electrically connected through the anisotropicconductive material 16, a semiconductor device can be manufactured by amethod of excellent reliability and productivity.

Since heat is applied to the semiconductor chip 20 by the jig 30, theanisotropic conductive material 16 is cured in the region of contactwith the semiconductor chip 20. In the region not contacting thesemiconductor chip 20 or the region apart from the semiconductor chip20, heat does not reach the anisotropic conductive material 16, so thatthe curing is incomplete. The curing of these regions is carried out inthe following step.

As shown in FIG. 1C, solder 34 is provided within and around theperiphery of the through holes 14 in the substrate 12. A cream solder orthe like may be used to form the solder 34 by printing. Alternatively,pre-formed solder balls may be mounted in the above-described position.

The solder 34 is then heated in a reflow step, and solder balls 36 areformed as shown in FIG. 1D. The solder balls 36 function as externalelectrodes. In this reflow step, not only the solder 34 but also theanisotropic conductive material 16 is heated. This heat cures theregions of the anisotropic conductive material 16 which are not yetcured. That is to say, of the anisotropic conductive material 16, theregion not contacting the semiconductor chip 20 or the region apart fromthe semiconductor chip 20, is cured in the reflow step of forming thesolder balls 36.

In the thus obtained semiconductor device 1, since the whole of theanisotropic conductive material 16 is cured, the possibility of theanisotropic conductive material 16 around the semiconductor chip 20coming apart from the substrate 12 and allowing the ingress of water,leading to migration of the interconnect pattern 10 is prevented. Sincethe whole of the anisotropic conductive material 16 is cured, theinclusion of water within the anisotropic conductive material 16 canalso be prevented.

Further in the semiconductor device 1, since the electrodes 22 providedon the surface 24 of the semiconductor chip 20 are covered by theanisotropic conductive material 16 which includes a shading material,light can be prevented from reaching this surface 24. Therefore,malfunction of the semiconductor chip 20 can be prevented.

FIGS. 2A and 2B show a modification of the first embodiment. In thesemodifications, the structure which is the same as in the firstembodiment is indicated by the same reference numerals, and descriptionof this structure and the effect of this structure is omitted. The sameis true for the following embodiments.

The step shown in FIG. 2A can be carried out after the step of FIG. 1Band before the step of FIG. 1C. In more detail, of the anisotropicconductive material 16, the region not contacting the semiconductor chip20 and the region apart from the semiconductor chip 20, are heated by aheating jig 38. The heating jig 38 is preferably provided with anonadhesive layer 39 formed of Teflon or the like having highnonadhesive properties to the anisotropic conductive material 16 that isan example of an adhesive, so that uncured anisotropic conductivematerial 16 does not adhere thereto. Alternatively, the nonadhesivelayer 39 may be provided on the anisotropic conductive material 16 thatis an example of an adhesive. Further, the anisotropic conductivematerial 16 as an example of an adhesive may be heated by a non-contactmethod. By this means, of the anisotropic conductive material 16, theregion not contacting the semiconductor chip 20 and the region apartfrom the semiconductor chip 20 can be cured. In place of a jig, a hotair blower or optical heater capable of localized heating may be used.

Alternatively, as shown in FIG. 2B, after the step of FIG. 1B and beforethe step of FIG. 1C, a reflow step may be carried out to electricallyconnect an electronic component 40 distinct from the semiconductor chip20 to the interconnect pattern 10. By means of this reflow step, of theanisotropic conductive material 16, the region not contacting thesemiconductor chip 20 and the region apart from the semiconductor chip20 is heated and cured. It should be noted that as the electroniccomponent 40 may be cited for example a resistor, capacitor, coil,oscillator, filter, temperature sensor, thermistor, varistor, variableresistor, or a fuse.

According to these modifications also, all of the anisotropic conductivematerial 16 can be cured, and the possibility of the anisotropicconductive material 16 coming apart from the substrate 12 and allowingthe ingress of water, leading to migration of the interconnect pattern10 can be prevented. Since the whole of the anisotropic conductivematerial 16 is cured, the inclusion of water can also be prevented.

After the above described steps, the substrate 12 may be cut in theregion in which the anisotropic conductive material 16 being an exampleof an adhesive spreads beyond the semiconductor chip 20.

This embodiment has been described with a substrate with interconnectson one surface only as the substrate 12, but is not limited to this, anda double-sided interconnect substrate or multi-layer interconnect may beused. In this case, in stead of disposing solder in the through holes,solder balls may be formed on lands provided on the surface opposite tothat on which the semiconductor chip is mounted. In place of solderballs other conductive projections may be used. The connection betweenthe semiconductor chip and the substrate may be carried out by wirebonding. These observations apply equally to the following embodiments.

In this embodiment, not only a thermosetting adhesive, but also ananisotropic conductive material 16 being an example of a thermoplasticadhesive may be used. A thermoplastic adhesive can be hardened bycooling. Alternatively, an adhesive which can be hardened by radiationsuch as ultraviolet light may be used. This applies equally to thefollowing embodiments.

Second Embodiment

A method of manufacturing the semiconductor device in accordance withthe second embodiment is shown in FIGS. 3A and 3B. This embodiment iscarried out following on from the first embodiment.

More specifically, in this embodiment, following on from the step ofFIG. 1D, the anisotropic conductive material 16 and substrate 12 areheld by a fixed blade 41, and cut by a movable blade 42 to a sizeslightly larger than the semiconductor chip 20, as shown in FIG. 3A,yielding a semiconductor device 2 shown in FIG. 3B. The cutting means isnot limited thereto, and any other available cutting means and holdingmeans can be applied. Since the substrate 12 is cut together with theanisotropic conductive material 16, the cut through the two is coplanar,and the entire surface of the substrate 12 is covered by the anisotropicconductive material 16. Therefore, the interconnect pattern 10 is notexposed, and moisture is prevented from reaching the interconnectpattern 10 and causing migration.

According to this embodiment, since the anisotropic conductive material16 is cut, it does not require to be previously cut to the same size asthe semiconductor chip 20 or slightly larger, and accurate positioningwith respect to the semiconductor chip 20 is not required.

It should be noted that this embodiment is an example of the anisotropicconductive material 16 and substrate 12 being cut after the solder balls36 are formed, but the timing of the cut is independent of the formationof the solder balls 36, as long as it is at least after thesemiconductor chip 20 has been mounted on the anisotropic conductivematerial 16. However, the anisotropic conductive material 16 ispreferably cured at least in the region of contact with thesemiconductor chip 20. In this case, mispositioning of the semiconductorchip 20 and interconnect pattern 10 can be prevented. If the anisotropicconductive material 16 is cured rather than uncured in the location ofthe cut, the cutting operation will be easier.

It should be noted that when the substrate 12 is cut, the whole of theanisotropic conductive material 16 being an example of an adhesive maybe cured in a single operation. For example, when the electrodes 22 ofthe semiconductor chip 20 and the interconnect pattern 10 areelectrically connected, to the whole of the anisotropic conductivematerial 16 being an example of an adhesive heat may be applied orcooling applied. When a thermosetting adhesive is used, a jig may beused which contacts both of the semiconductor chip 20 and the adhesivespreading out beyond the semiconductor chip 20. Alternatively, heatingmay be applied by means of an oven.

Third Embodiment

A method of manufacturing a semiconductor device in accordance with thethird embodiment is shown in FIGS. 4A and 4B show. In this embodiment,the substrate 12 of the first embodiment is used, and on the substrate12 is formed a protective layer 50. The protective layer 50 is such asto cover the interconnect pattern 10, preventing contact with water, andfor example solder resist may be used.

The protective layer 50 is formed around a region 52 that is larger inextent than the region in which the semiconductor chip 20 is mounted onthe substrate 12. That is to say, the region 52 is larger than thesurface 24 of the semiconductor chip 20 having the electrodes 22, andwithin this region 52 the lands (not shown in the drawings) forconnection to the electrodes 22 of the semiconductor chip 20 are formedon the interconnect pattern 10. Alternatively, the protective layer 50may be formed to avoid at least portions for electrical connection tothe electrode 20 of the semiconductor chip 20.

On such a substrate 12 an anisotropic conductive material 54 (adhesive)of a material which can be selected as the anisotropic conductivematerial 16 of the first embodiment is provided. It should be noted thatthe anisotropic conductive material 54 does not necessarily contain ashading material, but if it does contain a shading material then thesame effect as in the first embodiment is obtained.

In this embodiment, the anisotropic conductive material 54 is providedfrom the region of mounting of the semiconductor chip 20 to theprotective layer 50. That is to say, the anisotropic conductive material54 covers the interconnect pattern 10 and substrate 12 in the region 52in which the protective layer 50 is not formed, and is also formed tooverlap the edge of the protective layer 50 surrounding the region 52.Alternatively, the anisotropic conductive material 54 being an exampleof an adhesive may be provided on the semiconductor chip 20 side. Inmore detail, the description in the first embodiment applies.

The semiconductor chip 20 is then pressed toward the substrate 12 andheat is applied by the jig 30, as shown in FIG. 4A. Alternatively,pressure is applied at least between the semiconductor chip 20 and thesubstrate 12. In this way, the electrodes 22 of the semiconductor chip20 and the interconnect pattern 10 are electrically connected, as shownin FIG. 4B. Thereafter, in the same way as in the steps shown in FIGS.1C and 1D, solder balls are formed, and the semiconductor device isobtained.

According to this embodiment, the anisotropic conductive material 54 isnot only formed in the region 52 in which the protective layer 50 is notformed, but also formed to overlap the edge of the protective layer 50surrounding the region 52. Consequently, there is no gap between theanisotropic conductive material 54 and the protective layer 50, and theinterconnect pattern 10 is not exposed, so that migration can beprevented.

It should be noted that in this embodiment, it is preferable that theanisotropic conductive material 54 is cured also in the region spreadingbeyond the semiconductor chip 20. This curing step can be carried out inthe same way as in the first embodiment.

Fourth Embodiment

A method of manufacturing a semiconductor device in accordance with afourth embodiment of the present invention is shown in FIGS. 5A and 5B.In this embodiment, the substrate 12 of the first embodiment is used,and an anisotropic conductive material 56 (adhesive) is provided on thesubstrate 12. The difference between this embodiment and the firstembodiment is in the thickness of the anisotropic conductive material56. That is to say, as shown in FIG. 5A, in this embodiment thethickness of the anisotropic conductive material 56 is greater than thethickness of the anisotropic conductive material 16 shown in FIG. 1A.More specifically, the anisotropic conductive material 56 is thickerthan the interval between the surface 24 of the semiconductor chip 20having the electrodes 22 and the interconnect pattern 10 formed on thesubstrate 12. The anisotropic conductive material 56 is at leastslightly larger than the semiconductor chip 20. It should be noted thatit is sufficient for either of these thickness and size conditions to besatisfied.

As shown in FIG. 5A, the semiconductor chip 20 is then pressed towardthe substrate 12 and heat is applied by the jig 30, for example. Bydoing this, the anisotropic conductive material 56 surrounds a part orall of a lateral surface 28 of the semiconductor chip 20, as shown inFIG. 5B. Thereafter, solder balls are formed in the same way as in thesteps shown in FIGS. 1C and 1D, and the semiconductor device isobtained.

According to this embodiment, since at least part of the lateral surface28 of the semiconductor chip 20 are covered by the anisotropicconductive material 56, the semiconductor chip 20 is protected frommechanical damage. Moreover, since the anisotropic conductive material56 covers as far as a position removed from the electrodes 22, corrosionof the electrodes 22 and so on can be prevented.

Although the above embodiment has been described principally in terms ofa chip size/scale package (CSP) of face-down bonding (FDB), the presentinvention can be applied to any semiconductor device to which FDB isapplied, such as a semiconductor device to which Chip on Film (COF) orChip on Board (COB) is applied, or the like.

A circuit board 1000 on which is mounted a semiconductor device 1100fabricated by the method of the above described embodiment is shown inFIG. 6. An organic substrate such as a glass epoxy substrate or the likeis generally used for the circuit board 1000. On the circuit board 1000,an interconnect pattern of for example copper is formed to provide adesired circuit. Then electrical connection is achieved by mechanicalconnection of the interconnect pattern and external electrodes of thesemiconductor device 1100.

It should be noted that the semiconductor device 1100 has a mountingarea which can be made as small as the area for mounting a bare chip,and therefore when this circuit board 1000 is used in an electronicinstrument, the electronic instrument itself can be made more compact.Moreover, a larger mounting space can be obtained within the same area,and therefore higher functionality is possible.

Then as an example of an electronic instrument equipped with thiscircuit board 1000, a notebook personal computer 1200 is shown in FIG.7.

It should be noted that, whether active components or passivecomponents, the present invention can be applied to varioussurface-mounted electronic components. As electronic components, forexample, may be cited resistors, capacitors, coils, oscillators,filters, temperature sensors, thermistors, varistors, variableresistors, and fuses.

What is claimed is:
 1. A method of manufacturing a semiconductor devicecomprising: (a) disposing an adhesive at least between a surface of asubstrate on which an interconnect pattern is formed and a surface of asemiconductor chip on which electrodes are formed; (b) electricallyconnecting the electrodes to the interconnect pattern; (c) applyingenergy to a first part of the adhesive which is located on a firstregion of the substrate on which the semiconductor chip is mounted andhardening the first part; and (d) applying energy to a second part ofthe adhesive and hardening the second part after the step (c).
 2. Themethod of manufacturing a semiconductor device as defined in claim 1,wherein: the adhesive is thermosetting; the energy applied in the step(c) is pressure and heat; and the energy applied in the step (d) isheat.
 3. The method of manufacturing a semiconductor device as definedin claim 1, wherein the interconnect pattern and the electrodes areelectrically connected by conductive particles dispersed in theadhesive.
 4. The method of manufacturing a semiconductor device asdefined in claim 1, wherein before the step (a), the adhesive isdisposed on the surface of the semiconductor chip on which theelectrodes are formed.
 5. The method of manufacturing a semiconductordevice as defined in claim 1, wherein before the step (a), the adhesiveis disposed on the surface of the substrate on which the interconnectpattern is formed.
 6. The method of manufacturing a semiconductor asdefined in claim 1, wherein in the step (d), the energy is applied to aportion of the adhesive at which curing is not completed in the step(c).
 7. The method of manufacturing a semiconductor device as defined inclaim 2, wherein in the step (d), the adhesive is heated by a heatingjig.
 8. The method of manufacturing a semiconductor device as defined inclaim 7, wherein a nonadhesive layer having high nonadhesive propertiesto the adhesive is interposed between the heating jig and the adhesive,and the adhesive is heated.
 9. The method of manufacturing asemiconductor device as defined in claim 8, wherein the heating jig isprovided with the nonadhesive layer.
 10. The method of manufacturing asemiconductor device as defined in claim 8, wherein the nonadhesivelayer is disposed on the adhesive.
 11. The method of manufacturing asemiconductor device as defined in claim 1, wherein in the step (d), theenergy is applied to the adhesive without contacting the adhesive. 12.The method of manufacturing a semiconductor device as defined in claim1, further comprising a reflow step in which solder balls connecting tothe interconnect pattern are formed on the substrate, wherein the step(d) is carried out in the reflow step.
 13. The method of manufacturing asemiconductor device as defined in claim 1, further comprising a reflowstep in which in addition to the semiconductor chip, another electroniccomponent is electrically connected to the interconnect pattern, whereinthe step (d) is carried out in the reflow step.
 14. The method ofmanufacturing a semiconductor device as defined in claim 1, whereinafter the step (d), the substrate is cut in a region other than a regionin which the adhesive contacts with the semiconductor chip.
 15. Themethod of manufacturing a semiconductor device as defined in claim 1,wherein in the step (c), the adhesive is caused to surround at least apart of a lateral surface of the semiconductor chip.
 16. The method ofmanufacturing a semiconductor device as defined in claim 1, wherein theadhesive includes a shading material.